1. Field of Invention
The present invention relates to a method of manufacturing photo couplers. More particularly, the present invention relates to a method of manufacturing face-to-face structure photo couplers.
2. Description of Related Art
Photo couplers utilize light to transmit electronic signal. A photo coupler comprises a transmitter and a receiver. Firstly, an electronic signal triggers a light-emitting element such as a light emitting diode (LED) on the transmitter to emit light With a fixed wavelength. Then, the light is received by a light-receiving element on the receiver to reverse back to an electronic signal. The electronic signal is properly amplified to compensate transmission loss. Because a signal is transmitted by means of light from a transmitter to a receiver in a photo coupler, the photo coupler has good isolation to noise and can be used to prevent crosstalk between electronic signal from transmitter end and electronic signal from receiver end.
Because of the good isolation property of the photo couplers, the photo couplers are widely used in various circuits and become one of the most popular electronic devices.
However, because huge amount of consumption of photo couplers mass-manufactured by numerous producers, the price of photo couplers is getting cheaper and it is more difficult to generate profit. The production cost control of photo couplers becomes important for manufacturers to generate profit from photo couplers in such cheap price. The major cost in producing photo couplers is material cost. Therefore, there is a need to reduce the material cost of photo couplers to increase profit.